Quick response thermostatic valve



Aug. 8, 1967 c. s. BAlLEY QUICK RESPONSE THERMOSTATIC VALVE Filed Dec. 50, 1965 IN VENTOR. G/m'r/es 5 504% 1 United States Patent 3,334,812 QUICK RESPONSE THERMOSTATIQ VALVE Charles Stimets Bailey, Lockport, N.Y. assrgnor to General Motors Corporation, Detroit, M1ch., a corporahon of Delaware Filed Dec. 30, 1965, Ser. No. 517,763 6 Claims. (Cl. 236-34) ABSTRACT OF THE DISCLOSURE A thermostatic valve for controlling engine coolant flow to a radiator and in which a wax pellet type temperature sensitive motor for actuating the valve is insulated from the cold side of the valve and also in which engine block coolant pressure tends to open the valve when the latter is closed or almost closed by spring pressure.

State of the prior art The United States patent to Clifford et al. 2,881,616 shows a thermostatic valve which tends to close when engine block coolant pressure acts against it in supplementing spring pressure and a wax pellet type motor is employed on the hot or engine side of the valve to act against the coolant and spring pressure.

The United States patent to Woods 2,797,873 discloses a thermostatic valve which is influenced to open by engine block coolant pressure acting against it and a temperature sensitive wax is enclosed in a motor on the cold side of the valve for actuating the latter against a tension spring plus the coolant pressure.

Description of the invention In the drawings:

FIGURE 1 shows a portion of a cooling system for an internal combustion engine, a conduit being shown in section better to disclose the installation of a thermostatic valve incorporating features of the present invention;

FIGURE 2 is an enlarged sectional view of the thermostatic valve and the adjacent valve supporting parts of the cooling system of FIGURE 1;

FIGURE 3 is a sectional view looking in the direction of the arrows 33 in FIGURE 2; and

FIGURE 4 is a perspective view of a sleeve member utilized in the valve assembly of FIGURE 1.

In FIGURE 1 is shown an engine block connected to a radiator 12 by upper conduit means 14 and lower conduit means 16. The upper conduit means 14 serves to retain an annular flange 20 of a valve frame 22. This frame includes an imperforate cylindrical portion 24, an imperforate annular shoulder portion 26, an annular and downwardly converging frusto-conical seat portion 28 defining a main opening 29, and a bridge portion 30. Two openings such as the opening 32 are separated by the bridge portion 30. The frame 22 also includes a base plate 34 and two oppositely disposed legs 36 and 38 joined to the shoulder portion 26 to define opposite openings 40 and 42. The base plate 34 bears a flange 44 defining an opening 46.

An annular valve element 48 when closed, as in FIG- URE 1, is seated on the seat portion 28 and is resiliently held thereon by a coil spring 50 interposed between the base plate 34 and the valve element. The latter bears a cylindrical flange 52 encircling a plastic sleeve 54 freely received in the opening 46 of the frame 22. The sleeve 54 is clearly shown in FIGURE 4 to include a flange 56 at one end. This flange is adapted to press upwardly against an annular inner shoulder 58 of the valve element 48 because of a movable part or casing 60 of a pellet motor. The motor includes a plunger 62 fixed at 64 to the bridge portion 30. The motor is much like that ice the outside of the pellet motor casing 60. In a typical in-- stallation, the bleed notch 70 has been made with a radius of .035 inch and the volume of the space 72 has been made .026 cubic inch to give about 89 changes of coolant in the space 72 per minute. These figures are exemplary only and will vary in accordance with engine requirements.

In operation of the valve, the valve element 48 rises and permits flow of coolant to the radiator 12 as the waX 66 is heated. If the car transmission downshifts during high speed acceleration, coolant pressure on the car heater core does not rise unduly and this is because the pump pressure counteracts against the spring pressure and blows open the valve.

The bleed notch 70 works together with the space 72 to reduce and often to eliminate the possibility of cycling or hunting as the valve starts to open as the engine warms up. The plastic sleeve 54 cooperates with the casing 60 to provide a conduit or bleed passage for the coolant to bypass the main opening of the valve and to reach and wash the surface of the casing 60. The pellet power element or motor therefore quickly senses any engine water temperature change. The motor firmly operates on the bottom part of the wax melting curve (small volume change in the wax 61S per degree F. and slow valve element 48 movement per degree F.) during cold engine operation with the valve element 48 at or near its start-t'o-open position. These factors practically eliminate hunting as there is no delay or overshooting of temperature.

The sleeve 54 is made of insulation material such as ethyl cellulose plastic so that, the bleed coolant is not chilled by the coolant on the discharge side of the valve during engine warm-up periods. A number of plastic compositions are suitable and will withstand the temperature and anti-freeze solution conditions to be encountered.

I claim:

1. A thermostatic valve comprising a frame adapted to be mounted in a conduit, said frame having an annular seat defining a main opening with an inlet side and an outlet side, a valve element controlling said main opening, a thermostatic motor having two relatively movable parts, one of said parts being a plunger fixed to said frame on the said inlet side of said opening, the other of said parts containing temperature sensitive wax and being exposed at the outlet side of said opening, spring means interposed between said frame and said valve element at the outlet srde of said main opening and urging said valve element toward said annular seat, and a sleeve of heat insulating matenal interposed between said other part and said valve element and cooperating with said other part in defining a bleed passage by-passing said valve element and annular sea 2. A thermostatic valve as set forth in claim 1, said sleeve r eing a plastic cylinder with a flange at one end, and said flange having a radially extending notch therein.

3. A thermostatic valve as set forth in claim 1, said bleed passage being a radial notch in series with an annular space, and the latter being coaxial with said motor.

4. A thermostatic valve as set forth in claim 1, said frame including a base plate on the outlet side of said main opening, an opening in said base plate, and the said other part of said motor extending into said base plate opening.

I 5. A thermostatic valve as set forth in claim 1, said frame including a bridge traversing said main opening and supporting said one motor part, and said spring means being a coil spring surrounding said one motor part.

6. A thermostatic valve as set forth in claim 1, said frame including a flange and a base plate having an opening therein, legs connecting said base plate to said flange, said sleeve and other motor part extending into said base plate opening, an annular space between said other motor part and the said sleeve and extending the full corresponding lengths of the sleeve and other motor part, and a References Cited UNITED STATES PATENTS Woods 236-93 Cliiford et al. 73363 Freismuth 23634 Kurz et al. 23693 X EDWARD 1. MICHAEL, Primary Examiner. 

1. A THERMOSTATIC VALVE COMPRISING A FRAME ADAPTED TO BE MOUNTED IN A CONDUIT, SAID FRAME HAVING AN ANNULAR SEAT DIFINING A MAIN OPENING WITH AN INLET SIDE AND AN OUTLET SIDE, A VALVE ELEMENT CONTROLLING SAID MAIN OPENING, A THERMOSTATIC MOTOR HAVING TWO RELATIVELY MOVABLE PARTS, ONE OF SAID PARTS BEING A PLUNGER FIXED TO SAID FRAME ON THE SAID INLET SIDE OF SAID OPENING, WAX AND BEING EXPOSED CONTAINING TEMPERATURE SENSITIVE WAX AND BEING EXPOSED AT THE OUTLET SIDE OF SAID OPENING, SPRING MEANS INTERPOSED BETWEEN SAID FRAME AND SAID VALVE ELEMENT AT THE OUTLET SIDE OF SAID MAIN OPENING AND URGING SAID VALVE ELEMENT TOWARD SAID ANNULAR SEAT, AND A SLEEVE OF HEAT INSULATING MATERIAL INTERPOSED BETWEEN SAID OTHER PART AND SAID VALVE ELEMENT AND COOPERATING WITH SAID OTHER PART IN DEFINING A BLEED PASSAGE BY-PASSING SAID VALVE ELEMENT AND ANNULAR SEAT. 